Observed interannual variability of near‐surface salinity in the Bay of Bengal

Abstract

An in situ gridded data of salinity, comprising Argo and CTD profiles, has been used to study the interannual variability of near-surface salinity (within 30 m from sea surface) in the Bay of Bengal (BoB) during the years 2005-2013. In addition to the broad agreement with earlier studies on the north-to-south gradient of surface salinity and general features of seasonal variability of salinity, the data also revealed few episodes of enhanced freshening in the BoB. The observations showed distinct anomalous low salinity

Bay of Bengal: 2013 Northeast Monsoon Upper-Ocean Circulation

“…Sengupta et al (2006) The massive input of freshwater results in low salinity of the upperocean layer with a strong surface barrier layer stratification (Shetye et al, 1996;Vinayachandran et al, 2002). Pant et al (2015) find that SSS in the interior BoB reflects local freshwater forcing during the summer, whereas in winter it is governed more strongly by horizontal advection of riverine-origin water. SSS variability at interannual time scales responds more to the Indian Ocean Dipole (IOD)-a positive IOD leading to lower SSS-than to the El Niño-Southern Oscillation (ENSO).…”

Modeling Salinity Exchanges Between the Equatorial Indian Ocean and the Bay of Bengal

“…This water subsequently spreads out along isopycnals as it subducts deeper into the bay, advecting high-salinity water to the north in an eddying motion. As the figure shows, this water can be traced back the Ganges and Brahmaputra Rivers (Pant et al, 2015). Thus, it is essential to include the river discharges in the model to correctly simulate SSS in the northern BoB.…”

Freshwater in the Bay of Bengal: Its Fate and Role in Air-Sea Heat Exchange

“…In the second part of this article, we aim to better understand the annual distribution of freshwater within the bay and the mechanisms by which the fresh water is dispersed. The evolution of salinity in the Bay of Bengal on an annual time scale has been addressed by several modeling (Benshila et al, 2014;Akhil et al, 2014;Wilson and Riser, 2016) and observational (Sengupta et al, 2006;D' Addezio et al, 2015;Pant et al, 2015) studies, while considering the transport of freshwater. Here, we combine sea surface salinity from the Aquarius satellite mission with altimeter-derived sea surface velocity to interpret the time evolution of the surface salinity distribution.…”